Modern DC and AC motor drives provide features useful when using electric motors as final control elements. Some common features seen in both VSDs and VFDs are listed here:
Not only are some of these limiting parameters useful in extending the life of the motor, but they may also help extend the operating life of the mechanical equipment powered by the motor. It is certainly advantageous, for example, to have torque limiting on a conveyor belt motor, so that the motor does not apply full rated torque (i.e. stretching force) to the belt during start-up.
If a motor drive is equipped with digital network communication capability (e.g. Modbus), it is usually possible for a host system such as a PLC or DCS to update these control parameters as the motor is running.
In order for a VSD or VFD to properly and safely control an electric motor, that drive must be programmed with the motor’s nameplate data (voltage rating, current rating, maximum speed, etc.). Failure to properly configure an electronic motor drive with these “base” parameters may even result in damage to the motor, for example, if the drive is configured to output more current than the motor is rated for! As such, it is recommended that you first program these parameters into a motor drive before setting any other drive parameters.